caa a22 4500 477074227 CHVBK 20180405111435.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF02252851 doi (NATIONALLICENCE)springer-10.1007/BF02252851 Characterization of single K+ channels in Helix pomatia neurons [Elektronische Daten] [E. Lukyanetz, A. Sotkis] The measurements of unitary outward ion currents in unidentified neurons of the snailHelix pomatia with the patch-clamp technique in a cell-attached configuration showed the presence of several types of K+ channels. We investigated three types of K+ channels: with big (75 pS, BKC), medium (22 pS, MKC), and small (6.2 pS, SKC) unitary conductance. BKC and MKC were activated at a membrane potential of about −30 mV, whereas SKC were activated at more negative potentials, with opening probability of the latter channels significantly decreasing at potentials more positive than −30 mV. Pharmacological investigation showed that BKC and MKC channel activity disappeared after 8-10 min of cell patching with a pipette solution containing 60 mM Cs+, whereas MKC channels remained unaffected. BKC and MKC were proved to be more sensitive to TEA (20 mM), whereas SKC were selectively sensitive to 4-AP (10 mM). Cd2+ (100 µM) in the pipette solution decreased the unitary conductance of BKC channels by 55 % and that of MKC channels by about 31 %. In contrast, the unitary conductance of SKC channels was not changed by the above blocker. Bath application of 10 µM 5-HT showed that MKC were suppressed by 5-HT, whereas SKC and BKC were insensitive to this transmitter. It is supposed that BKC can be classified as big-conductance Ca2+-dependent K+ channels (KCa) or to 5-HT-sensitive K+ channels (S-type channels), while MKC correspond to intermediate-conductance KCa, and SKC channels comply well with the characteristics of A-type K+ current. Plenum Publishing Corporation, 1997 Lukyanetz E. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut Sotkis A. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut Neurophysiology Kluwer Academic Publishers-Plenum Publishers 28/6(1996-11-01), 193-201 0090-2977 28:6<193 1996 28 11062 https://doi.org/10.1007/BF02252851 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02252851 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lukyanetz E. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut NATIONALLICENCE 700 1- Sotkis A. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut NATIONALLICENCE 773 0- Neurophysiology Kluwer Academic Publishers-Plenum Publishers 28/6(1996-11-01), 193-201 0090-2977 28:6<193 1996 28 11062 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer